﻿using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace Orange.Lib.Effective
{
    public class ConstantUse
    {
        //只有数字或字符串能被声明为const(编译时常量), 其他类型的不行
        private const double PI = Math.PI;

        //readonly (运行时常量), 只能在构造器或初始化时被赋值 (初始化先于构造函数)
        private readonly DateTime curtime = DateTime.Now;

        private static int i ;
    }
}
